git-merge

#!/usr/bin/env bash

###
### git-merge: Add convenience options to git-merge(1).
###

BASENAME="$(basename $0)"
ERR_NOTREPO="Not a Git repository."
ERR_NO_PREV_BRANCH="Unable to merge, no previous branch could be found."

ARGV=()

while [[ $# -gt 0 ]]; do
	case "$1" in
		-h|--help)
			exec $GIT merge --help

			exit 0
		;;
		-T|--trim)
			shift

			if [[ ! "$($GIT rev-parse --is-inside-work-tree)" ]] 2>/dev/null; then
				printf '%s: %s\n' "$BASENAME" "$ERR_NOTREPO"

				exit 1
			fi

			LASTBRANCH="$($GIT check-ref-format --branch @{-1} 2>/dev/null)"

			if [[ $? -gt 0 ]]; then
				printf '%s: %s\n' "$BASENAME" "$ERR_NO_PREV_BRANCH"

				exit 1
			fi
		;;
		*)
			ARGV+=("$1")

			shift
		;;
	esac
done

if [[ ! "$($GIT rev-parse --is-inside-work-tree)" ]] 2>/dev/null; then
	printf '%s: %s\n' "$BASENAME" "$ERR_NOTREPO"

	exit 1
fi

$GIT merge "${ARGV[@]}"

# On a successful merge where --trim was specified and a previous branch (ref) exists.
if [[ $? -eq 0 ]] && \
   [[ -n "$LASTBRANCH" ]]; then
	$(echo $($GIT branch --list) | grep "$LASTBRANCH" >/dev/null 2>&1)

	# If $LASTBRANCH is a valid, local branch, attempt soft delete.
	[[ $? -eq 0 ]] && exec $GIT branch -d $LASTBRANCH
fi